that XC sounds just like my 06 yfz. I went through 7-8 motors in it. It turned into project quad, 06 cbr 600rr motor in it now that has yet to be finished, going on 5 years now lol. My built 540 is running great. Probably 80 hours on it and runs awesome still.
2008 525XC Twin Air 5pin filter, Factory 540, Vertex 12.5:1, 807 cam, +1 Steel Valves, 43.5mm and Fast Ranchero carb mods, Bill's Pipe, Headwork by DRG, Baldwin Oil Cooler, Trail Tech Vapor, Eagle Eye HID Kit, Mino hiflo pump, Engine Ice. Cletus....>2009 CanAm Outlander 800R Camo. Muzzy Slip-on, PCV tuned, Eagle Eye HID kit, HPG shock w/HD spring kit, Dalton DBO800 Clutch Kit, 27" Executioners, STI HD3 Wheels. '06 LTR 450. Yoshi slip on, cherry bomb and FCI intake. Wifes bike.